Not applicable.
Not applicable.
(1) Technical Field
The invention pertains to lift-roof covers for use with load beds of light trucks, providing improved access to the load bed and extending functions to other uses, with major focus upon achieving these benefits in a manner best accommodating manufacturing and distribution processes broadly in use relative to conventional fixed mount cab high covers (caps) of the prior art. Applicable US classifications include 296/100.1, 100.6 hinged load covers, 296/165 expansible or collapsible vehicle body, 296/176 expansible/collapsible from a first to a second configuration for camping. The disclosure describes key improvements beyond the concept described by U.S. Pat. No. 5,102,185, these improvements providing simplification in manufacturing processes and improvements in convenience of installation and operation to levels approaching those for conventional fixed mount caps (cab high covers) of the prior art. These improvements also increase the functional reliability of the complete lift-roof cover system and make possible enhanced aesthetic appeal by eliminating obvious appearance differences from conventional fixed mount caps of the prior art which have demonstrated highest user acceptance levels. In particular, objection has been made to separation lines between the forward wall and the lift-roof/cap shell when these are visible in side view. The application to a new use of existing technology for hinging and weather sealing rear hatch assemblies for fixed mount caps of the prior art overcomes this deficiency, while supporting functional and economic benefits associated with use of technology which is familiar to practitioners of the art to which the invention pertains.
(2) Description of Related Art
Through review of the prior art defined in patents relating to pickup truck load bed covers issued subsequent to Lake, U.S. Pat. No. 5,102,185, it can be seen that much effort has been focused on inventing alternate means to provide improved access for loading/unloading and facilitating adaptation to uses beyond cargo protection while also making available a roof height equal to or greater than that of the vehicle cab. Examples include the following:
Ekonen et al, U.S. Pat. No. 5,104,175, and Hemdon, U.S. Pat. No. 5,951,095, describe transformable cover assemblies which unfold from a low profile on the load bed to provide full enclosure with a roof level equivalent to that of a cab high, fixed mount cap of the prior art. However, they add complexity while giving up significant degrees of security and integrity of appearance with the vehicle when in the cab high operating mode.
Plamondon, U.S. Pat. No. 6,149,217, Alexa, U.S. Pat. No. 6,000,745, Moberly, U.S. Pat. No. 5,443,295, and Hanning, U.S. Pat. No. 6,471,282, describe retractible flexible covers of cab height which fail to provide the security and integrated (with vehicle) appearance provided by most fixed mount, molded caps.
Aragon et al, U.S. Pat. No. 5,516,182, Herzberg et al, U.S. Pat. No. 5,203,603, and Hutchinson, U.S. Pat. No. 5,655,809, describe telescoping cab high covers having rigid outer paneling. These concepts provide better cargo security, but add significant complexity and also fail to provide the fully integrated appearance provided by most conventional, fixed mount, molded caps.
Fowler, U.S. Pat. No. 6,471,280, describes a cover with hard molded shell but, in order to provide improved loading access, requires removal of the shell, an obvious inconvenience.
Baldwin, U.S. Pat. No. 6,439,647, Dence, U.S. Pat. No. 6,394,532, and Lambden, U.S. Pat. No. 6,007,137, describe cab high rigid covers pivoting from one or both sides in a manner providing increased interior volume as desirable for adaptation to camping or improved side loading access. However they fail to provide improved access from the rear suitable for loading popular wheeled equipment.
Harkins, U.S. Pat. No. 5,209,543, describes an apparatus for enclosures such as pickup bed tops, including a pair of folding top panels longitudinally hinged for closing along the top centerline. In order to achieve the benefits of lift-roof improved access loading from the rear, considerable and costly complexity is added.
Medlin, U.S. Pat. No. 5,595,418, and Enninga, U.S. Pat. No. 5,104,175, describe means for mounting a cap to a load bed in ways accommodating pivotal rotation of the complete camper shell about a forward axis by lifting from the rear. However, significant complexity appears to be added in hardware and processes necessary for installation and acceptable function. Furthermore, sealing at the forward wall to load bed interface is not addressed.
Moore et al., U.S. Pat. No. 5,421,833, describes a camper shell intended for mounting directly to a truck frame on a vehicle assembly line, adaptable to having its roof pivotally raised from the rear and having flexible walls for camping attached and/or removed. Moore et al appears focused on application of lift-roof functional benefits via a high production volume vehicle assembly process requiring high levels of manufacturing tooling investment and does not appear to address needs of manufacturing and distribution systems in place within the conventional cap industry.
The concepts cited above provide various benefits beyond those provided by conventional fixed mount caps of the prior art. In most cases compromises are introduced which are evidently unacceptable to most purchasers of fixed mount, molded caps (historically comprising the primary market for pickup truck covers), who demand an appearance well integrated with styling of the vehicle, together with secure, weatherproof enclosure of the load bed to a height matching that of the vehicle cab. It would appear that Enninga and Medlin are able to retain all key functional and aesthetic benefits provided by conventional caps as long as they are used in the closed condition. When in the open condition cargo space is compromised, due to intrusion of the cap forward wall, which moves rearward as the cap shell is raised and introduces issues with respect to sealing to the load bed forward wall. Also, complexity introduced in the components and associated processes necessary for installation become of particular concern where installation may be completed at multiple locations by individuals with limited experience relative to the product. Therefore, objects of my invention include to provide the benefits of improved access for loading and easy adaptation to alternate uses while minimizing complexity in the installation process and/or costs in added hardware and avoiding compromises relative to benefits already provided by conventional fixed caps of the prior art.
Grise, U.S. Pat. No. 4,452,482, and McGaughey et al, U.S. Pat. No. 4,461,185, describe hatch frame construction for pickup truck caps including an integral hinge for supporting a hatch door in a weatherproof manner with location close to the cap roof edge. These patents are of referent interest in describing adaptation of radius door technology to lift-roof cover application
Ely et al, U.S. Pat. No. 6,179,350, describes a draw latch and various means for providing resistance to keep the members of a latch assembly in a variety of given positions and addresses need for manually raising a catch in order to effect disengagement.
Gromotka, U.S. Pat. No. 5,478,125, describes a draw latch in which rotation of the lever initially disengages the catch and positive contact between the lever and latch arm at a distance from the latch pivot causes the hook arm to kick out. Objects include to provide these functions with parts which are few, durable and reliable in all functions.
P. R. Gley et al, U.S. Pat. No. 3,519,298, describes a positive lock for toggle catch, or draw latch, permitting concomitant release of the catch and movement of the handle to an open position.
The above draw latch patents address need for one-handed convenience in operation. Various methods are described as used in the prior art for positioning handles and latch arms to support convenient operation. Plastic inserts have been employed where corrosion from exposure to the elements could otherwise impair function. Metal-to-metal frictional methods are commonly employed in order to support low cost. However, it would appear that, in practice, most friction or interference methods tend to result in high efforts and/or variation in effort due to wear and/or manufacturing variability. Such methods may be adequate to temporarily retain latch handles to an open position, because full hand strength may be conveniently applied to effect release. However, the control effort with respect to a latch arm pivoting from a latch handle needs to be relatively low in order to support convenient operation, which requires moving the latch arm independently of the handle either immediately before moving the handle, or simultaneously with handle operation, but in any case as a fluid one-handed movement. Accordingly it is an object to provide a draw latch which supports convenient positioning of component parts in operation by applying reliable methods to draw latches having other characteristics suited to lift-roof cover application. This may be best achieved with concepts depending on zero resistance beyond that of a free pivot and force of gravity, or otherwise with a more reliable method of providing frictional resistance than generally employed in the prior art.
To meet expectations with respect to product attributes broadly demanded within the primary market containing the majority of potential lift-roof cover users, these attributes must not be significantly compromised. Of particular importance for meeting needs of customers through the total delivery chain are convenience in manufacturing, distribution and installation as well as in end use. Accordingly, objects include to provide a forward wall and attaching system which may be conveniently pre-assembled and stored ready for assembly with minimal rework to a molded reinforced plastic cover of the prior art (generally limited to removal of material as needed to attach added hardware), together with an attaching system simplifying the process of installation to a vehicle load bed while supporting shipping, handling, storage methods employed for conventional caps of the prior art. Subassemblies incorporating draw latches and lift assist struts (plus rigid support struts and rigid support strut engagement means) are also used supporting these objectives. Draw latches have been uniquely developed for lift-roof application to provide reliable operating convenience.
To satisfy users, opening and dosing operations must be conveniently completed by one person. Available draw latches of the prior art have been found lacking in functions necessary for such convenience. Latches on each side of the cover need to be simultaneously operated with simple movement of one hand, both in closing/latching and releasing/raising the cover. This requires reliable friction means and operating geometry ensuring that, when the lift-roof cover has been lowered on the load bed and the latch handle is operated to effect engagement, the engaging latch arm can be conveniently positioned to complete engagement and, after operation to effect release, remain in a position allowing unimpeded lift-roof raising or lowering.
A preferred forward wall is adapted from technology applied to rear hatch doors for conventional fixed caps of the prior art, generally referred to as radius doors in the trade to which the invention pertains. Adaptation of extruded-frame-hinge-within-extruded-frame pivotal attachment allows the forward wall to lift-roof structure interface joint to be inboard of the lift-roof side walls and hidden as viewed from outside of the vehicle, a valuable aesthetic benefit. Related benefits of applying this proven technology to a new use include simplified systems for lift-roof to forward wall hinging/sealing and orientation/position adjustment of the forward wall relative to load bed.
A novel forward wall to load bed attaching system is in the form of a linkage which supports multiple functions, including providing (a) means for adjusting location of the forward wall on the load bed and orientation of the forward wall to achieve effective sealing in closed condition between forward wall, lift-roof and load bed; (b) means of conveniently completing installation or removal from the vehicle load bed without fully removing attaching fasteners (c) in conjunction with lift assist struts, means to hold the forward wall to a closed position relative to the lift-roof with all components secured above a plane across lower edges of the molded lift-roof, so that the complete lift-roof cover may be shipped, handled and stored prior to installation using the same methods employed for a conventional fixed mount cap of the prior art.
In use, the lift assist struts are mounted between the load bed and lift-roof structure in a manner (a) facilitating sealing at the forward wall to lift-roof interface by loading the lift-roof forward against the forward wall and (b) adding lateral constraint in location of the lift-roof relative to load bed, providing protection from damage which might otherwise result, for example, from severe wind gusting immediately on raising the lift-roof.
A durability concern for conventional caps of the prior art has related to effects of severe shake, as associated with some modes of heavy duty model pickup operation on rough road surfaces. Without countermeasures, lift-roof structure side wall forward lower edges have increased sensitivity to lateral vibration compared with a conventional cap, in which the side walls are integral with the forward wall. Such vibration is prevented by incorporation of side wall retainer means between the lift-roof structure and the forward wall structure. To accommodate dimensional variability, these units incorporate means for adjustment of relative lateral position.
The use of frame-hinged-within-frame radius door fabrication technology in a forward wall to lift-roof attachment system results in forward loads imposed by the lift assist struts being transferred to the forward wall by the hinge interface when the lift-roof is in a raised position. Rigidity of the hinge interface protects the seal from excessive compression in upper locations, so that with the lift-roof dosed and without countermeasures, forward loading is transferred primarily to the lower edges of the inverted U shaped lift-roof side wall to forward wall interface. This results in the seal and inner and outer frames deforming toward the lower edges to a degree eventually impairing both sealing and positioning of the lift-roof on the load bed. To avoid these conditions and provide precise control of closed location of the lift-roof relative to the forward wall, means of adjustable forward wall closure stop are needed. This is achieved cost effectively by integrating such means of adjustable stop with the adjustable lift-roof side wall retainers at each side of the lift-roof cover. These integrated units allow closure position to be set simultaneously with side wall retainer engagement during assembly, protecting sealing function between the lift-roof and the forward wall and preventing vibration of lift-roof side walls relative to the forward wall, as well as increasing security from unauthorized forced entry.
Designing for flex under severe operating conditions has become broadly recognized as necessary for structures such as tall buildings and bridges in order to achieve reliability with acceptable cost. This concept may have been less broadly recognized in automotive accessory applications and, perhaps as a result, fracturing of early molded cap shells was not uncommon, particularly in cold climates. Therefore, manufacturers have developed caps which better absorb flex. Severe operation results in significant torsional flexing of most pickup truck frames, much of which is transmitted to the load bed. If ignored, the effects add cost in reliability and other functional respects. Flex may be less of a concern with low frequency twist, as induced by normal off-road operation. However, pickups, particularly heavy duty models, may induce severe lateral shake due to high rate suspension systems which, under some light load operating modes on rough road surfaces, instead of fully absorbing irregularities, cause high frequency shake to be transmitted to the load box. Accordingly, it is an object of the invention to address issues of structural flex under operating conditions in lift-roof cover application.
In summary, the object of my invention is to add novel improvements with respect to convenience, cost and reliability affecting assembly, distribution, installation and use while providing a combination of advantages relative to fixed mount covers of the prior art as described in the parent U.S. Pat. No. 5,102,185 and fully maintaining the benefits already provided by conventional bed covers of the prior art. Further objects and advantages will become readily apparent to those skilled in the art to which the invention pertain upon reference to the following detailed description of a preferred embodiment.